IPv4 subnetting worksheet with answers

Free printable IPv4 subnetting worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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Name: ____________________   Date: ____________

1.Easy
/2011111111111111111111000000000000network bitshost bits

How many usable host addresses H are there in an IPv4 subnet with prefix /20?

/20
H =
2.Easy
fourth octet of /26112816403201608040201oneszeros

Write the subnet mask of a /26 network in dotted-decimal notation. What is the value x of its fourth octet?

/26
x =
3.Medium
/?11111111111111111111100000000000network bitshost bits

A department needs 1147 host addresses in a single subnet. What is the longest prefix length p (smallest subnet) that is big enough?

1147 hosts
p =
4.Medium
255.255.255.12811111111111111111111111110000000network bitshost bits

A subnet uses the mask 255.255.255.128. How many usable host addresses H does it have?

255.255.255.128
H =
5.Hard
third octet = 254112816413211618141201networkhost

A host has the address 172.20.254.69/22. What is the third octet x of its network address?

172.20.254.69/22
x =
6.Hard

The network 192.168.112.0/24 is split with VLSM for these LANs: A: 14 hosts, B: 5 hosts, C: 41 hosts, D: 113 hosts. Subnets are allocated from .0 upwards, the LAN with the most hosts first, each with the smallest subnet that fits. What is the fourth octet x of the network address of LAN A?

A: 14B: 5C: 41D: 113
x =

Answer key

  1. 1. H = 4094
  2. 2. x = 192
  3. 3. p = 21
  4. 4. H = 126
  5. 5. x = 252
  6. 6. x = 192

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